JPH08237929A - Rotary actuator - Google Patents

Abstract

PURPOSE: To increase holding power at a specified driving position without increasing power consumption by installing a pair of magnetic members on an outer face of a rotation-side member for dividing magnetic flux and installing a permanent magnet and a plurality of stator blocks on a fixed-side member and thereby forming magnetic paths which have 1 small magnetic energy loss. CONSTITUTION: A rotation-side member B is constituted of a rotary shaft of a rotor 30 and a pair of rotor yokes 31, 32 which are fastened on an outer face of the rotary shaft 30. On the other hand, a fixed-side member A are constituted of a pair of upper and lower circular arc body yokes 1, 2, a pair of right and left stator yokes 3, 4, and connection yokes 5, 6, 7, 8 which connect ends of the yokes 1, 2, 3, 4 and all these parts constitute a cylindrical yoke section. Then, a permanent magnet 14 is fixed on an inner face of the upper circular arc body yoke 1 and a stator yoke 18 is fixed on an inner face of the lower circular arc body yoke 2. Because of this structure, magnetic paths D1 , D2 , D3 , and D4 are formed and thereby magnetic energy of the permanent magnet 14 can be used efficiently and holding power at a specified position can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary actuator used for driving an idle speed control electromagnetic valve, for example.

[0002]

2. Description of the Related Art Conventionally, as a rotary actuator, for example, there is a "rotational driving device" described in JP-B-64-2023, page 5, FIGS.

This "rotary driving device" (hereinafter referred to as a rotary actuator) is a member (first yoke) forming a first magnetic path and a coil for generating a magnetic flux in the axial direction of the first magnetic path. And a space provided in the first magnetic passage, in which the first magnetic passage has a wide axial width and a narrow constriction in a direction orthogonal to the axial direction, and a space formed in the space. The rotating permanent magnet, which is rotatably arranged and is magnetized in the radial direction with two poles, is substantially in contact with the member forming the first magnetic path, and is in the rotation axis direction of the rotating permanent magnet and the axis of the first magnetic path. Ferromagnetic yoke member (second yoke) provided in directions orthogonal to each other and forming a second magnetic path.
It was equipped with.

That is, in this conventional example, a rotating permanent magnet having two poles magnetized on the rotor side is used, and the rotating permanent magnet is used as the first permanent magnet.
The magnetic resistance of the magnetic path of the rotating permanent magnet is changed by rotating in a space (long in the axial direction of the first magnetic path) formed in the magnetic path of, and the neutral stable position (both narrowed portions are A torque that returns in the connecting direction, that is, the direction in which the magnetic flux of the rotating permanent magnet is orthogonal to the axial direction of the first magnetic path) is exerted. Then, by energizing the coil means in this state, a magnetic flux is generated in the axial direction of the first magnetic path, which is a direction orthogonal to the magnetic flux of the rotating permanent magnet, and the strength of this magnetic flux (energization to the coil means is applied. The rotating permanent magnet can be rotated from the neutral stable position to an arbitrary rotation angle position and held at that position according to the magnitude of the electric current.

Further, in this conventional example, by the ferromagnetic yoke member (second yoke) forming the second magnetic path,
The magnetic resistance of the magnetic path of the rotating permanent magnet in the neutral stable position is reduced to increase the torque that returns the rotating permanent magnet to the neutral stable position, thereby increasing the torque change rate (gradient) with respect to the rotation angle of the rotating permanent magnet. That is, the holding force at a predetermined rotational position is increased.

[0006]

However, the above-described conventional rotary actuator has the following problems. That is, in the rotary actuator of the conventional example, as described above, the space provided in the member (first yoke) forming the first magnetic path formed of the ferromagnetic material is magnetized into two poles. The rotary permanent magnet is arranged, that is, the magnetic field formed around the rotary permanent magnet is short-circuited around the entire circumference by the member (first yoke) forming the first magnetic path. A part of the magnetic flux generated in (1) is shunted to the side of the first magnetic path having the coil means to reduce the magnetic flux applied in the direction orthogonal to the magnetic flux of the rotating permanent magnet. The magnetic reluctance change of becomes gentle, and the torque change rate (gradient) with respect to the rotation angle is small,
The holding force against the disturbance torque at the predetermined rotation position becomes small.

Therefore, the rotational position fluctuates greatly depending on the magnitude of the disturbance torque acting on the rotating permanent magnet. For example, when a valve provided in a part of the intake passage of the engine is directly driven by this rotary actuator, the rotational torque as a disturbance acts on the rotating permanent magnet on the rotor side due to the flow force generated in the valve. By changing the rotational position, the valve opening changes, which causes a problem that hunting occurs in the engine speed.

Even if the second magnetic path is formed by the ferromagnetic yoke member, the entire circumference is short-circuited by the member (first yoke) forming the first magnetic path. No significant improvement effect can be obtained. Further, in the conventional example, instead of forming the narrowed portion, the member (first yoke) forming the first magnetic path is divided into two with a slight slit portion, so that the magnetic field around the rotary permanent magnet is reduced. A plan to eliminate the short circuit is also proposed, but with a slit
Since the divided first yokes are connected by the first magnetic path, the first magnetic path itself forms a magnetically short-circuited path with respect to the rotating permanent magnet, and therefore, No significant improvement effect can be obtained.

Therefore, either the coil magnetomotive force required to rotate the rotating permanent magnet is increased by increasing the value of the current passed through the coil, or a rare earth magnet having a strong magnetic force is used as the rotating permanent magnet to solve the above problems. Although it is possible to improve the point, in the former case, power consumption increases, and in the latter case, rare earth magnets are much more expensive than ferrite magnets, which leads to cost increase. Will cause problems. It should be noted that it is difficult to form a cylindrical ferrite magnet into a substantially cylindrical shape because cracks occur during the manufacturing process.

The present invention has been made by paying attention to the above-mentioned conventional problems, and enhances the holding force against external force at a predetermined drive position without increasing power consumption and cost. It is an object of the present invention to provide a rotary actuator capable of performing the above.

[0011]

In order to achieve the above object, a rotary actuator according to a first aspect of the present invention is provided with a fixed side member formed in a substantially annular shape and rotatably provided in the fixed side member. The turning side member has an outer circumferential surface formed in an arc shape on the outer circumference of the turning side member, and is magnetically separated from each other through magnetic flux separating portions between both ends in the turning direction. Magnetic flux shunting means consisting of a pair of magnetic flux shunting means provided on the inner surface side of the fixed-side member facing the arcuate outer circumferential surfaces of both the magnetic flux shunting means and the arcuate outer circumferential surfaces of the respective magnetic flux shunting means. A pair of stators facing each other in an arc shape with a small gap is provided, and at least one of the pair of stators generates a magnetic flux in a direction orthogonal to the rotating direction of the rotating side member and Control magnetomotive force Is provided with an effective coil means, and two magnetic fluxes are magnetized on the inner surface side of the fixed-side member facing one side of the both magnetic flux separation portions in a direction orthogonal to the rotation direction of the rotation-side member. One end of the flow dividing means is provided with permanent magnets facing each other in an arc shape with a predetermined small gap,
On the inner surface side of the fixed side member facing the other side of both the magnetic flux separating portions, the other side of the two magnetic flux shunting means is projected in the direction orthogonal to the rotating direction of the rotating side member of the two magnetic flux shunting means. A stator having end portions each having a predetermined small gap and facing each other in an arc shape is provided, and the fixed side member has a permanent magnet on a side opposite to a side of the rotating side member facing each magnetic flux shunting means. And a pair of stators, and a magnetic path forming means that magnetically communicates between the stator and the pair of stators.

A rotary actuator according to a second aspect of the present invention comprises a fixed side member formed in a substantially annular shape and a turning side member rotatably provided in the fixed side member. On the outer periphery of the member, there is provided a magnetic flux shunting unit having a pair of magnetic members each having an outer peripheral surface formed in an arc shape and magnetically separated from each other between both ends in the rotation direction through magnetic flux separating portions. On the inner surface side of the fixed-side member facing the arcuate outer peripheral surfaces of both the magnetic flux shunting means, a pair of arcuate outer peripheral surfaces of the respective magnetic flux shunting means are arcuately facing each other with a predetermined small gap. A stator is provided, and at least one of the pair of stators is provided with coil means capable of generating a magnetic flux in a direction orthogonal to the rotating direction of the rotating side member and controlling the magnetomotive force thereof. Both magnetic flux Parts and on the inner surface side of the fixed-side member facing each 2 in the direction orthogonal to the rotating direction of the rotation-side member
A pair of permanent magnets, which are pole-polarized and one end of each of the magnetic flux shunting means has a predetermined small gap and face each other in an arc shape, is provided. The magnetic flux shunting means is provided with magnetic path forming means for magnetically communicating between the permanent magnets and the pair of stators on the side opposite to the side facing the magnetic flux shunting means.

According to a third aspect of the present invention, in the rotary actuator according to the first or second aspect, the coil means provided in the one stator can switch the direction of the magnetic flux generated in the stator between normal and reverse directions. The means configured to control the magnetomotive force of each of the forward and reverse magnetic fluxes was adopted.

According to a fourth aspect of the present invention, in the rotary actuator according to the third aspect, the coil means provided on the one stator includes two coils that generate magnetic fluxes in mutually opposite directions. The means.

According to a fifth aspect of the present invention, in the rotary actuator according to the fourth aspect, only one coil means is energized during on-duty and only the other coil means is energized during off-duty, based on the duty signal. The magnetomotive force generated in both stators is controlled by variably controlling the duty ratio of the duty signal.

According to a sixth aspect of the present invention, in the rotary actuator according to the first or second aspect, the pair of stators are provided with both magnetic flux shunting means in a direction orthogonal to a rotating direction of the rotating side member. A means for generating a magnetic flux having the same pole on the facing side and providing a coil means capable of controlling the magnetomotive force is provided.

According to a sixth aspect of the present invention, in the rotary actuator according to the sixth aspect, only one coil means is energized during on-duty and only the other coil means is energized during off-duty, based on the duty signal. The magnetomotive force generated in the pair of stators is controlled by variably controlling the duty ratio of the duty signal.

[0018]

In the rotary actuator according to the first aspect of the present invention, since it is configured as described above, when the coil means is not energized, the magnetic flux of the permanent magnet becomes the magnetic flux diverting means in one magnetic flux diverting portion. Through the small gaps formed between the facing surfaces of the two magnetic flux shunting means, and the flow is shunted by the magnetic flux shunting means, and further passes through the small gaps formed between the facing surfaces of the magnetic flux shunting means and the stators. , Then return to the permanent magnet via each of the magnetic path forming means (or in the opposite direction),
In addition to the two divided magnetic paths, the magnetic flux of the permanent magnet passes through the small gaps formed between the two magnetic flux diverting means and is diverted to both magnetic flux diverting means, and then the other magnetic flux diverting portion. In the shunt, after passing through the small gaps formed in the surface facing the stator in each of the above and flowing into the stator, it returns to the permanent magnet via both magnetic path forming means (or in the opposite direction to the above). The two magnetic paths thus formed are formed.

At this time, when the areas of the two small gaps formed on the facing surfaces between the magnetic flux shunting means and the permanent magnet, that is, the cross-sectional areas of the two magnetic paths are not the same (and (The area of both small gaps formed on the surface facing the stator, that is, when the cross-sectional areas of the two magnetic paths are not the same)
Causes a magnetic reluctance difference that the magnetic reluctance on the side of the smaller magnetic passage becomes larger than that on the side of the larger magnetic passage cross-sectional area. The torques that rotate the rotation-side member in the increasing direction act in directions opposite to each other,
Therefore, both torques are evenly balanced, that is, the areas of both small gaps formed on the facing surfaces between the magnetic flux shunting means and the permanent magnets, and the facing areas between the magnetic flux shunting means and the stator. The return torque for returning the turning-side member to the neutral stable position where the areas of both the small gaps formed on the surface are the same is always working.

Therefore, when both coil means are not energized, the turning side member can be held at the neutral stable position. From this neutral stable position, the turning side member can move in either direction. When rotated, a return torque to the neutral stable position is generated which is proportional to the amount of change in magnetic resistance due to the rotation, and the strength of this return torque holds the rotation side member against disturbance at the predetermined rotation position. It becomes the magnitude of power.

Next, when a magnetic flux is generated in one of the stators by energizing the coil means, the strength of the magnetic flux in the four magnetic paths becomes non-uniform, so that the four small gap portions have the same area. In this state, the balance of the magnetic resistance in both magnetic paths is lost, so torque is generated to rotate the rotating member to a position where the magnetic resistance is balanced again, and this torque causes the rotating member to become neutral. It can be rotated from a stable position to a predetermined position and held at that position.

The magnetic flux of the permanent magnet includes a magnetic path composed of the permanent magnet, both magnetic flux shunting means, both stators and both magnetic path forming means, and permanent magnet, both magnetic flux shunting means, stator and both magnetic path forming means. Since it has a structure in which only the magnetic path constituted by (3) flows and there is no other short-circuit path that causes magnetic energy loss as in the conventional example, the magnetic energy of the permanent magnet can be efficiently used.
Therefore, it is possible to increase the holding force against the external force at the predetermined driving position without increasing the power consumption and the cost.

Further, in the rotary actuator according to claim 2, the stator on the magnetic flux separating portion side in the rotary actuator according to claim 1 is changed to a permanent magnet, and the magnetic flux of the permanent magnet causes the magnetic flux of the magnetic path. Is stronger, that is, the holding force against external force at a predetermined drive position can be increased.

Further, in the rotary actuator according to the third aspect of the invention, when the magnetic flux is generated by the coil means in either one of the forward and reverse directions with respect to the one stator, the rotary side member is rotated in a predetermined direction from the neutral stable position. When it is moved and a magnetic flux is generated in the opposite direction to the above, the rotating side member can be rotated in the opposite direction from the neutral stable position.

Further, in the rotary actuator according to the fourth aspect, in the third aspect, the magnetic flux generated in the stator is switched by switching the energization of the two coils.

According to a fifth aspect of the present invention, in the rotary actuator according to the third aspect, only one coil side is energized during on-duty and only the other coil side is energized during off-duty, based on the duty signal. By variably controlling the duty ratio of the duty signal, it is possible to control the magnetomotive force in each of the forward and reverse magnetic flux directions generated in the stator, that is, when the duty ratio is 50% and the rotating side member is at the neutral stable position. Retained,
By increasing / decreasing the duty ratio from 50%, it is possible to rotate the rotating side members in mutually opposite directions about the neutral stable position.

Further, in the rotary actuator according to the sixth aspect, by energizing either one of the coil means provided in both of the pair of stators, the rotary side member is moved in a predetermined direction from the neutral stable position. By rotating and energizing the other side of the coil means, the rotating side member can be rotated in the opposite direction from the neutral stable position.

According to a seventh aspect of the present invention, in the rotary actuator according to the sixth aspect, based on the duty signal, only one coil means is energized during on-duty and only the other coil means is energized during off-duty. The magnetomotive force generated in both stators can be controlled by variably controlling the duty ratio of the duty signal.
At 50%, the turning side member is held at the neutral stable position, and by increasing or decreasing the duty ratio from 50%, the turning side member can be turned in the opposite directions about the neutral stable position.

[0029]

Embodiments of the present invention will now be described in detail with reference to the drawings. (First Embodiment) FIG. 1 is a sectional view (II line in FIG. 2) showing a rotary actuator of a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG. In the figure,
A is a fixed member, and B is a rotary member.

First, the fixed member A will be described. A pair of upper and lower arcuate body yokes 1 and 2 each made of a ferromagnetic material, and a pair of left and right stator yokes 3 and 4, respectively.
A substantially cylindrical yoke portion is formed by the connecting yokes 5, 6, 7, and 8 that connect the end portions of the respective yokes 1, 2, 3, and 4, and the opening portions at both ends of the cylindrical yoke portion are not connected. Aluminum caps 9 and 10 made of magnetic material are attached,
At the center of both caps 9 and 10, the bearing 1
1, 12 are press-fitted and fixed. In addition, 13 is a screw for connecting the respective members.

On the inner peripheral side of the upper arc-shaped body yoke 1, a permanent magnet 14 having two poles magnetized in the radial direction of the cylindrical yoke portion is adhered and fixed. A ferrite magnet is used as the permanent magnet 14, and the inner peripheral surface is formed in an arc shape centered on the axial center portion of the cylindrical yoke portion, and the outer peripheral side has a N pole and the inner peripheral side has a S pole. It is magnetized in two directions.

On the inner peripheral side of the lower arc-shaped body yoke 2, the permanent magnet 14 and the stator 18 of the target shape are bonded and fixed around the axial center of the cylindrical yoke portion.

On the inner surfaces of the left and right stator yokes 3 and 4, stators 15 and 16 made of a ferromagnetic material are fastened and fixed by screws 17a and 17b, respectively. The inner peripheral surfaces of both the stators 15 and 16 are formed in an arc shape with the axial center of the cylindrical yoke portion as the center, similarly to the permanent magnet 14, and an insulating coating (not shown) is provided on the outer peripheral side. The coils 19 and 20 for generating magnetic flux in the radial direction are wound around the stators 15 and 16 via the.

Next, the rotating member B will be described.
The rotating side member B includes a rotor rotating shaft 30 and a pair of rotor yokes 3 bonded and fixed to the outer periphery of the rotor rotating shaft 30.
1 and 32.

The rotor rotary shaft 30 is made of stainless steel (SUS304) which is a non-magnetic material, and both ends of the rotor rotary shaft 30 are rotatably supported by the bearings 11 and 12.

The rotor yokes 31 and 32 constitute the magnetic flux shunting means in the claims, and are formed of a ferromagnetic material in a semicircular arc shape, and in FIG. Between the end faces, voids a ₁ and a ₂ having magnetically separable widths are formed as magnetic flux separating portions, respectively. More specifically, both rotor yokes 31, 32
The outer peripheral surface of the end portion on the side of the void a _{1 in FIG.
1} and b ₂ face the arc-shaped inner peripheral surface of the permanent magnet 14, and the outer peripheral surfaces of the other ends of both rotor yokes 31 and 32 have small gaps c ₁ and c ₂ , respectively. While facing the arc-shaped inner peripheral surface of the stator 18, the outer peripheral surfaces of the intermediate portions of both rotor yokes 31 and 32 are respectively small gaps d ₁ and d _2.
Are provided so as to face the arc-shaped inner peripheral surfaces of both stators 15 and 16.

Therefore, in FIG. 1, the magnetic flux of the permanent magnet 14 is divided into the left and right in the upper body yoke 1, and then the upper connecting yokes 5 and 6 and the stator yokes 3 and 4 (in the above claims). The magnetic path forming means in the range of 1), and the small gaps d ₁ and d via the respective stators 15 and 16.
_{The two} divided magnetic paths D pass through ₂ and flow into the rotor yokes 31 and 32, respectively, and further pass through the small gaps b ₁ and b ₂ and return to the permanent magnet 14.
_{In addition to 1} , D ₂ , after being split into the left and right in the upper body yoke 1, the upper connecting yokes 5 and 6, the stator yokes 3 and 4, the lower connecting yokes 7 and 8 (requested above) Of the magnetic path forming means in the range of ( ₁₎ , merges with the stator 18, passes through the small gaps c ₁ and c ₂ , respectively, and is divided into the rotor yokes 31 and 32, and further, the small gaps b ₁ and b. _{In this state, two} shunted magnetic paths D ₃ and D ₄ are formed, each passing through ₂ and returning to the permanent magnet 14.

Next, the coil drive circuit shown in FIG. 3 will be described. One ends of the coils 19 and 20 are connected to the positive pole of the battery Ba through the terminal 21,
The other ends of the coils 19 and 20 are connected to the terminal 2
NPN transistors 24 and 2 via 2 and 23 respectively
5 and the emitter sides of the NPN transistors 24 and 25 are both grounded. In the figure, 26 and 27 are coils 19 and 20, respectively.
On the other hand, it is a surge absorbing diode that is installed in parallel.

The duty signal S (D) is input to the base side of the NPN transistor 25 on the coil 20 side, and the duty signal S (D) is input to the base side of the NPN transistor 24 on the coil 19 side via the inverter 28.
(D) is input, the duty signal S (D) is turned on for a period of time Ta so that only the NPN transistor 25 is turned on to allow the current of the battery Ba to flow to the coil 20 side, and the duty signal S (D) is turned off. Tb allows only the NPN transistor 24 to conduct so that the current of the battery Ba flows to the coil 19 side. When the coils 19 and 20 are energized, the flow direction of the magnetic paths D ₃ and D ₄ of the pair of left and right magnetic paths divided by the magnetic flux of the permanent magnet 14 and passing through the stator 18 is the same. However, the other magnetic path D ₁ , D
_The wires are wired so as to generate magnetic fluxes φ ₁ and φ ₂ in the direction opposite to the flow direction of ₂ . As described above, the coils 19 and 20 and the coil drive circuit constitute the coil means in the claims.

Next, the operation of the embodiment will be described. (B) When the coil is de-energized Since there are many leakage circuits in the magnetic circuit and it is difficult to analyze the flow of the magnetic flux accurately, the main flow of the magnetic flux will be explained here. In the state, the magnetic flux of the permanent magnet 14 is in the state of flowing through the _four magnetic paths D ₁ , D ₂ , D ₃ and D ₄ as described above.

At this time, from the state of FIG.
Rotating in either direction, both rotor yokes 3
₁ , 32 and the areas of the small gaps b ₁ and b ₂ formed on the facing surfaces between the permanent magnets 14 and the rotor yokes 31,
32, the area of the small gaps c ₁ and c ₂ formed on the opposing surfaces between the stator 18 and the stator 18, that is, the pair of left and right magnetic paths D
₁ , D ₂ and the other pair of left and right magnetic paths D ₃ , D ₄
For cross-sectional area is no longer the same, respectively, although the magnetic resistance difference of magnetic resistance increases the larger the smaller magnetic path side to the magnetic passage side of the cross-sectional area respectively are generated, both small clearance portion b _1, b ₂ and both small gaps b ₁ , b ₂
The torques that rotate the rotor yokes 31 and 32 in the directions in which the magnetic resistances in (1) and (2) are respectively reduced (increase in area) act in the directions opposite to each other.
At the neutral stable position (state of FIG. 1) where the areas of both small gaps b ₁ and b ₂ and both small gaps b ₁ and b ₂ are the same, the rotor rotation shaft 3
The return torque for returning 0 is always in operation.

Therefore, when the coils 19 and 20 are not energized, the rotor rotary shaft 30 can be held at the neutral stable position. The neutral stable position is the rotor rotation angle θ = 0 °. When the rotor rotation shaft 30 rotates in either direction from this position, a return torque to the neutral stable position is generated in proportion to the amount of change in the magnetic resistance due to the rotation, and the intensity of this return torque depends on the rotor rotation. It becomes the magnitude of the holding force against the disturbance at the predetermined rotor rotation angle θ of the shaft 30.

FIG. 4 shows a return torque T characteristic with respect to the rotor rotation angle θ. As shown in FIG. 4, assuming that the counterclockwise rotation of the rotor rotation shaft 30 is a minus angle and the clockwise rotation is a plus angle, the coil is The return torque T characteristic when the rotor rotary shaft 30 is rotated in the non-energized state is as shown in [I]. Note that the rotor rotation angle θ and the return torque T are in the same direction, that is, when the return torque T is positive, the rotor rotation angle θ is increased, and when the return torque T is negative, the rotor rotation angle θ is decreased. , Therefore R in FIG.
The position of the rotor rotation angle θ = 0 ° shown in ₂ is the rotor rotation shaft 3
The neutral position is 0. Then, the rate of change (gradient) of the return torque T with respect to the rotor rotation angle θ of the rotor rotation shaft 30.
The larger is the magnetic resistance change rate in the magnetic paths D ₁ and D ₂ and the magnetic paths D ₃ and D _4, the larger is the holding force against disturbance.

Therefore, the magnetic flux of the permanent magnet 14 is passed through the magnetic path D.
By concentrating on ₁ , D ₂ , D ₃ , and D ₄ , the magnetic energy possessed by the permanent magnet 14 can be utilized as the return torque T to the maximum efficiency.

(B) When the coil is energized Next, when the coils 19 and 20 are energized with the duty signal S (D) as shown in FIG. 3, the duty signal S (D) is supplied.
During the on-time Ta of, the coil 20 is energized only on the coil 20 side, so that the direction of φ ₂ is the same on the stator 16 side (the same as the magnetic path D ₄ due to the magnetic flux of the permanent magnet 14 and the magnetic path D ₂ ). Generates a magnetic flux in the direction opposite to
Further, during the off time Tb, the coil 19 is energized only,
As a result, the direction of φ ₁ (permanent magnet 1
The magnetic flux of _No. 4 is the same as the flow direction of the magnetic path D _{3 but} is opposite to the flow direction of the magnetic path D ₁ ). However, in reality, the drive frequency of 1 / (Ta + Tb) is about 100 to 500 Hz, and the time constants of the coils 19 and 20 are sufficiently larger than that, so that the coils 19 and 20 have an off duty ratio ( = Tb × 10
It is considered that an average current corresponding to 0 / (Ta + Tb)% or an on-duty ratio (= Ta × 100 / (Ta + Tb)%) flows and an average magnetic flux for each average current is generated in the stators 15 and 16. be able to.

As described above, when the coils 19 and 20 are energized, the permanent magnet 14 is applied to both the stators 15 and 16.
When the magnetic fluxes φ ₁ and φ ₂ are generated in the directions opposite to the flow directions of the respective magnetic paths D ₁ and D ₂ shunted by the magnetic flux of
The magnetic fluxes φ ₁ and φ ₂ weaken the magnetic fluxes of the magnetic paths D ₁ and D ₂ by the permanent magnet 14, while the magnetic paths D ₁ and D ₂ are weakened.
The magnetic flux of ₃ , D ₄ will be strengthened.

Therefore, when the on-duty ratio is 50% (and the off-duty ratio is also 50%) and the strengths of both magnetic fluxes φ ₁ and φ ₂ in both stators 15 and 16 are uniform, both magnetic paths D ₁ and D ₂ are generated. _Since the strength of both magnetic fluxes between the two and between the two magnetic paths D ₃ and D ₄ is also maintained in a uniform state, the rotor rotation shaft 30 has the rotor rotation angle θ = 0 shown by R ₂ in FIG. ° Neutral stable position is maintained.

Next, when the on-duty ratio is 100% (off-duty ratio is 0%), the magnetic flux φ ₁ on the side of the stator 15 around which the coil 19 is wound is 0%, and the stator 16 around which the coil 20 is wound. the magnetic flux phi ₂ side is 100% by flux of the magnetic path D ₂ side through the stator 16 side is weakened by the magnetic flux phi _2, intensified by the magnetic flux D ₄ of the magnetic path D ₃ side by the magnetic flux phi ₂ As a result, the magnetic flux strengths between the two magnetic paths D ₁ and D ₂ and between the two magnetic paths D ₃ and D ₄ become non-uniform, so that both small gaps b ₁ , b ₂ and When the small gaps c ₁ and c ₂ have the same area, the magnetic resistances between the magnetic paths D ₁ and D ₂ and between the magnetic paths D ₃ and D ₄ are out of balance. The direction in which the magnetic resistance is balanced again, that is, the rotor rotation shaft A positive torque is generated to rotate the rotor in the clockwise direction, and this positive torque causes the rotor rotation shaft 30 to rotate at the rotor rotation angle θ = + 20 ° shown by R ₃ in the figure.
Return torque T shown in [II] in the figure
Depending on the characteristics, it can be held at the rotor rotation angle θ position.

Further, when the on-duty ratio is 0% (the off-duty ratio is 100%), contrary to the above, the coil 1
The magnetic flux φ ₁ on the side of the stator 15 around which 9 is wound is 100%,
The magnetic flux φ ₂ around the stator 16 around which the coil 20 is wound is 0%.
Therefore, a negative torque for rotating the rotor rotation shaft 30 in the counterclockwise direction is generated, and the negative torque causes the rotor rotation shaft 30 to rotate at the rotor rotation angle θ = −20 shown by R ₁ in FIG.
The rotor can be rotated to the position of .degree. And held at the rotor rotation angle .theta. Position by the return torque T characteristic shown in [III] of FIG. This means that the rotor rotation angle θ can be controlled to an arbitrary position within the range of −20 ° to + 20 ° by the on-duty ratio control.

FIG. 5 shows a variable characteristic of the rotor rotation angle θ with respect to the on-duty ratio.

FIG. 6 shows small gaps b ₁ and b ₂ and
The ratio of the length of the gap a _{1 in} the rotation direction is determined by the rotor rotation shaft 30.
FIG. 3 is an explanatory view represented by the rotation angle of the rotor rotation shaft 3 in the neutral stable position as shown in FIG.
The rotation angle range of ₀ is θ ₀ , the rotation angle of the arc portion of the inner diameter side of the permanent magnet 14 is θ _m , the rotation angle of the gap a is θ _s , and the small gap b.
_When the rotation angle of the _two portions is θ _r (= θ _m / 2-θ _s / 2), the rotation angle θ _s of the air gap a can be set within the range of 10 ° to 20 °. 2 division demultiplexing on desirable in, also a small gap b difference 1 and half of the _second partial rotation angle range theta ₀ of the rotation angle theta _r and the rotor rotational axis 30 of the (theta _r - [theta]
_s / 2) can be set within the range of 5 ° to 10 ° by setting the linear torque variable characteristic within the rotation angle range θ ₀ of the rotor rotation shaft 30 and the linear variation of the rotor rotation angle θ with respect to the duty ratio. It is desirable for obtaining the characteristics.

As described above, the rotary actuator of the first embodiment has the following effects. The magnetic flux of the permanent magnet 14 is mainly
And both stators 15 and 16 and both rotor yokes 31 and 3
2 and the magnetic paths D ₁ and D ₂ and the permanent magnet 14, the stator 18, and the rotor yokes 31 and 32.
Since there is no other short-circuit path that flows through the magnetic paths D ₃ and D ₄ via and and causes the magnetic energy loss as in the conventional example, the magnetic energy of the permanent magnet 14 can be efficiently transferred. Therefore, it is possible to increase the holding force against the disturbance torque at the predetermined rotation angle θ position without increasing the power consumption due to the increase of the energization current and the cost increase due to the use of the expensive permanent magnet. become able to.

By providing the coils 19 and 20 on both the pair of left and right stators 15 and 16, it is possible to obtain a wide rotor rotation angle range θ ₀ .

Next, another embodiment of the present invention will be described. In addition, in the other embodiments, the same reference numerals are given to substantially the same components in principle as those of the first embodiment, the description thereof will be omitted, and only the differences will be described.

(Second Embodiment) In the rotary actuator of the second embodiment shown in FIG. 7, the connecting yokes 5, 6, 7, 8 are formed by forming the body yokes 1, 2 in a flat plate shape.
This is a modified example in which is omitted, and substantially the same operational effect as that of the first embodiment can be obtained.

(Third Embodiment) A rotary actuator of a third embodiment shown in FIG. 8 shows a modification in which the stator 18 in the first embodiment is replaced with a permanent magnet 29.

That is, in this embodiment, as the permanent magnet 29, a ferrite magnet is used, which is magnetized in two radial directions so that the inner peripheral sides of the permanent magnet 14 are different from each other. Therefore, due to the magnetic flux of the permanent magnet 29, the magnetic flux passes through the small gaps c ₁ and c ₂ formed between the rotor yokes 31 and 32, respectively, and is shunted to the rotor yokes 31 and 32. d ₁ , d
After passing through ₂ and flowing into each of the stators 15 and 16, it returns to the permanent magnet 29 via each of the stator yokes 3 and 4, the lower connecting yokes 7 and 8 and the lower body yoke 2.
Thus, the two magnetic paths D ₅ and D ₆ are formed.

Therefore, in this embodiment, the small gaps d ₁ and d ₂ are formed by the new pair of divided magnetic paths D ₅ and D _6.
It is possible to increase the rate of change in the magnetic resistance in the above condition, whereby the holding force against the disturbance torque at the predetermined rotation angle θ position can be further increased.

The embodiment has been described above with reference to the drawings. However, the specific structure is not limited to this embodiment, and the present invention is applicable even if there are design changes and the like within the scope not departing from the gist of the present invention. include.

For example, in the embodiment, the coil means is provided on both the pair of left and right stators 15 and 16, but only one of them may be provided. However, in this case, the rotation range of the rotation-side member B is halved. However, in one of the stators 15 or 16, the directions of magnetic flux are opposite to each other.
A state in which a coil means having two coils is provided (for example,
By setting the coils 19 and 20 in the above embodiment wound around one stator 15 or 16 at the same time), it is possible to obtain the same rotation range as when the coil means is provided on both stators 15 and 16. Become.

In the embodiment, the magnetic flux separating portions are magnetically separated from each other by the air gaps (a ₁ and a ₂ ), but they are magnetically separated by interposing a non-magnetic member. May be.

[0062]

As described above, in the rotary actuator according to the first aspect of the present invention, as described above, the magnetic flux of the permanent magnet is the permanent magnet, both magnetic flux shunting means,
Only two magnetic paths formed by both stators and both magnetic path forming means and only two magnetic paths formed by the permanent magnet, both magnetic flux shunting means, stator and both magnetic path forming means flow as in the conventional example. By adopting a structure in which other short-circuit paths that cause magnetic energy loss do not exist, the magnetic energy of the permanent magnet can be efficiently used, and therefore, increase in power consumption and cost increase can be achieved. The effect that the holding force against the external force at the predetermined rotation position can be increased is obtained.

In the rotary actuator according to the second aspect of the present invention, the magnetic flux in the magnetic path is strengthened by replacing the stator on the magnetic flux separating portion side of the rotary actuator according to the first aspect with a permanent magnet.
As a result, it is possible to obtain an effect that the holding force against the external force at the predetermined drive position can be further increased.

In the rotary actuator according to a third aspect of the present invention, the direction of the magnetic flux generated in the stator of the coil means provided in the one stator can be switched between normal and reverse, and the magnetomotive force of each forward and reverse magnetic flux can be controlled. By doing so, it is possible to rotate the rotating side members in mutually opposite directions about the neutral stable position, that is, it is possible to widen the rotating range of the rotating side member. To be

According to a fourth aspect of the present invention, in the rotary actuator according to the third aspect, the coil means provided on the one stator includes two coils for generating magnetic fluxes in opposite directions to the stator. With the configuration, the turning-side member can be turned in mutually opposite directions about the neutral stable position by controlling the energization of the two coils.

According to a fifth aspect of the present invention, in the rotary actuator according to the fourth aspect, only one coil means is energized during on-duty and only the other coil means is energized during off-duty based on the duty signal. By controlling the magnetomotive force generated in both stators by variably controlling the duty ratio of the duty signal, the rotation side members are opposite to each other around the neutral stable position only by variably controlling the duty ratio. Can be rotated in any direction.

Further, in the rotary actuator according to a sixth aspect of the present invention, the pair of stators are provided with a magnetic flux having a same pole on the side facing both the magnetic flux shunting means in the direction orthogonal to the rotating direction of the rotating side member. Since the coil means capable of generating and controlling the magnetomotive force is provided, the rotating side members can be rotated in the opposite directions about the neutral stable position, that is, the rotating The effect that the driving range of the side member can be widened is obtained.

Further, in the rotary actuator according to a seventh aspect of the present invention, according to the sixth aspect, based on the duty signal, only one coil means is energized during on-duty and only the other coil means is energized during off-duty. By controlling the magnetomotive force generated in the pair of stators by variably controlling the duty ratio of the duty signal, it is possible to rotate the rotating side members in opposite directions about the neutral stable position. it can.

[Brief description of drawings]

FIG. 1 is a sectional view taken along line I-I of FIG. 2 showing a rotary actuator according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG. 1 showing the rotary actuator of the first embodiment of the present invention.

FIG. 3 is a diagram showing a coil drive circuit in the rotary actuator of the first embodiment of the present invention.

FIG. 4 is a characteristic diagram of return torque with respect to a rotor rotation angle in the rotary actuator of the first embodiment of the present invention.

FIG. 5 is a variable characteristic diagram of the rotor rotation angle with respect to the on-duty ratio in the rotary actuator of the first embodiment of the present invention.

FIG. 6 is an explanatory diagram showing, in terms of a rotation angle, a ratio of lengths in the rotation direction of both small gap portions and a gap portion in the rotary actuator of the first embodiment of the present invention.

FIG. 7 is a sectional view showing a rotary actuator of a second embodiment of the present invention.

FIG. 8 is a sectional view showing a rotary actuator according to a third embodiment of the present invention.

[Explanation of symbols]

A fixed side member B drive side member D ₁ magnetic path D ₂ magnetic path D ₃ magnetic path D ₄ magnetic path D ₅ magnetic path D ₆ magnetic path a ₁ air gap (magnetic flux separation portion) a ₂ air gap (magnetic flux separation portion) b ₁ Small gap b ₂ Small gap c ₁ Small gap c ₂ Small gap d ₁ Small gap d ₂ Small gap 1 Body yoke (magnetic passage forming means) 2 Body yoke (magnetic passage forming means) 3 Stator yoke (Magnetic passage forming means) 4 Stator yoke (magnetic path forming means) 5 Connection yoke (magnetic path forming means) 6 Connection yoke (magnetic path forming means) 7 Connection yoke (magnetic path forming means) 8 Connection yoke (magnetic path forming means) 14 Permanent magnet 15 Stator 16 Stator 18 Stator 19 Coil (coil means) 20 Coil (coil means) 29 Permanent magnet 31 Rotor yoke (magnetic flux shunting means) 32 Rotor yoke (magnetic flux shunting means)

Claims (7)

[Claims] 1. A fixed-side member formed in a substantially annular shape and a turning-side member rotatably provided in the fixed-side member, wherein an outer peripheral surface is provided on an outer periphery of the turning-side member. Magnetic flux shunting means formed of a pair of magnetic members, which are formed in an arcuate shape and are magnetically separated from each other by magnetic flux separating portions, are provided between both ends of the rotating direction, and the circles of the both magnetic flux shunting means are provided. A pair of stators are provided on the inner surface side of the fixed-side member facing the arc-shaped outer peripheral surface, which face the arc-shaped outer peripheral surfaces of the magnetic flux shunting means in a circular arc shape with a predetermined small gap, respectively. At least one of the stators is provided with a coil means capable of generating a magnetic flux in a direction orthogonal to the rotating direction of the rotating member and controlling the magnetomotive force thereof, and facing one side of the both magnetic flux separating portions. On the inner surface side of the fixed side member A permanent magnet is provided, which is magnetized in two poles in a direction orthogonal to the rotating direction of the rotating side member and has one end of each of the magnetic flux shunting means facing each other in an arc shape with a predetermined small gap. , The other side of the two magnetic flux shunting means projecting in the direction orthogonal to the rotating direction of the rotating side member of the two magnetic flux shunting means on the inner surface side of the fixed side member facing the other side of the two magnetic flux separating portions. Is provided with stators facing each other in an arc shape with a predetermined small gap, and the fixed side member is permanently provided on the side opposite to the side facing the magnetic flux shunting means of the rotating side member. A rotary actuator comprising magnetic path forming means for magnetically communicating between the magnet and the pair of stators and between the stator and the pair of stators. 2. A fixed-side member formed in a substantially annular shape and a turning-side member rotatably provided in the fixed-side member, wherein an outer peripheral surface is provided on the outer circumference of the turning-side member. Magnetic flux shunting means formed of a pair of magnetic members, which are formed in an arcuate shape and are magnetically separated from each other by magnetic flux separating portions, are provided between both ends of the rotating direction, and the circles of the both magnetic flux shunting means are provided. A pair of stators are provided on the inner surface side of the fixed-side member facing the arc-shaped outer peripheral surface, which face the arc-shaped outer peripheral surfaces of the magnetic flux shunting means in a circular arc shape with a predetermined small gap, respectively. At least one of the stators is provided with coil means capable of generating a magnetic flux in a direction orthogonal to the rotating direction of the rotating side member and controlling the magnetomotive force thereof, and fixed to face both the magnetic flux separating portions. On the inner surface of the side member A pair of permanent magnets, which are magnetized in two poles in a direction orthogonal to the rotating direction of the rotating side member, and have one end of each of the magnetic flux shunting means facing each other in an arc shape with a predetermined small gap. The fixed side member is provided with a magnetic path for magnetically communicating between the permanent magnets and the pair of stators on opposite sides of the rotating side member facing the magnetic flux shunting means. A rotary actuator comprising means. 3. The coil means provided on the one stator is configured so that the direction of the magnetic flux generated in the stator can be switched between normal and reverse directions, and the magnetomotive force of each forward and reverse magnetic flux can be controlled. Claim 1 or Claim 2
The rotary actuator according to. 4. The rotary actuator according to claim 3, wherein the coil means provided on the one stator includes two coils that generate magnetic fluxes in mutually opposite directions in the stator. 5. Based on the duty signal, only one coil means is energized during on-duty and only the other coil means is energized during off-duty, and the duty ratio of the duty signal is variably controlled to generate in both stators. The rotary actuator according to claim 4, wherein the magnetomotive force to be controlled is controlled. 6. The pair of stators can generate a magnetic flux having the same pole on the side facing the magnetic flux shunting means in a direction orthogonal to the rotating direction of the rotating side member, and can control the magnetomotive force thereof. The rotary actuator according to claim 1 or 2, further comprising a flexible coil means. 7. A pair of both stators based on the duty signal, by energizing only one coil means during on-duty and energizing only the other coil means during off-duty and variably controlling the duty ratio of the duty signal. The rotary actuator according to claim 6, characterized in that a magnetomotive force generated in the rotary actuator is controlled.